Reduced acquisition time for thallium myocardial perfusion imaging with large field cadmium-zinc-telluride SPECT/CT cameras: An equivalence study

BACKGROUND

Cadmium-zinc-telluride (CZT) SPECT/CT cameras with large field of view offer a higher sensitivity than conventional Anger cameras. This prospective study aimed to determine the equivalence between a conventional protocol and a reduced acquisition time protocol for 201-Thallium myocardial perfusion imaging (MPI) using a whole-body CZT SPECT camera.

METHODS AND RESULTS

Stress MPI was obtained for 103 consecutive patients on a DISCOVERY-CZT camera. Images were anonymized and post-processed to simulate a 25% (D75 dataset) and 50% (D50 dataset) decrease in total recorded counts. Concerning the number of segments displaying a tracer uptake < 70% of maximum intensity per patient, equivalence was demonstrated for both count-reduced datasets with a good inter-observer agreement (between 0.90 and 0.88). When comparing the full-vs-D75 datasets and full-vs-D50 datasets, mean difference was 0.06 segment (CI95: [- 0.15;0.27], P < 0.001) and 0.518 segment (CI95: [0.28;0.76], P < 0.001) respectively. Inter-observer agreement was also moderate to good concerning the number of pathological segments (between 0.6 and 0.7) and excellent for functional parameters.

CONCLUSION

Whole-body CZT SPECT/CT cameras allow to reduce 201-Thallium MPI injected activity or acquisition time by 50% with an equivalence in the number of segments displaying a tracer uptake < 70% of maximum intensity and with a good inter-observer agreement.

Implementation of a systematic comprehensive geriatric assessment for elderly patients suspected of pulmonary hypertension

BACKGROUND

The phenotype of patients seen for a suspicion of pulmonary hypertension has changed, with an increasing age and frequency of comorbidities. Selection of elderly patients, in whom a classical work-up is mandatory, is challenging. Comprehensive geriatric assessment (CGA) has modified the management of elderly patients with cancer. Pulmonary hypertension (PH) shares with cancer a functional impact and may evolve rapidly, depending on the group of PH. We assessed the impact of a systematic CGA in patients over 70 years old referred for a suspicion of PH.

METHODS

A standardised CGA was performed on every patient older than 70 years old, referred for a PH suspicion, before considering invasive tests for diagnosis and treatment, between July 2014 and May 2019. Our primary aim was to describe the impact of CGA on the decision to stop or pursue the recommended diagnostic work-up for PH.

RESULTS

Among the thirty-one patients evaluated [mean age 81,5 (72-91) years], a negative CGA leads to stop the diagnostic work-up in eleven patients. Among the nineteen remaining patients, sixteen had confirmed PH, with half being chronic thromboembolic pulmonary hypertension.

CONCLUSIONS

Our study indicates that comprehensive geriatric assessment could be an excellent first screen for elderly patients referred for a PH suspicion. Involving a geriatric physician stopped the investigations in one third of patients. In patients with a favourable CGA, PH was confirmed in most of the cases, with chronic thromboembolic pulmonary hypertension being the first cause of PH.